Image pickup apparatus

ABSTRACT

An image pickup apparatus includes an image pickup device configured to capture an image regarding an object image; an object detector detecting a specific object in the captured image; an image-capturing-information obtaining unit obtaining image capturing information from a predetermined area set in an image capturing area; a determiner determining whether or not the image capturing information regarding the specific object is obtainable from the predetermined area; and a display controller controlling a position display shown on a display unit, the position display indicating a position of the specific object. The display controller changes a display mode of the position display in accordance with the result of the determination performed by the determiner.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display technique for use in an imagepickup apparatus.

2. Description of the Related Art

In a single-lens reflex image pickup apparatus, an object is generallyobserved through an optical finder. However, another type of imagepickup apparatus has also been proposed which has an electronic finderfunction for displaying an object on a monitor as a moving image.

An example of an image pickup apparatus having the electronic finderfunction successively captures auxiliary images regarding an objectimage with an auxiliary image pickup device included in a finder opticalsystem, and displays a live view based on the auxiliary images on amonitor. Some image pickup apparatuses that are capable of displayingthe live view have a function of detecting specific objects in the liveview image and displaying the positions of the specific objects on themonitor.

In general, a single-lens reflex image pickup apparatus includes an AFmodule for receiving object light to detect focus information (distancemeasurement information) of the object. The AF module outputs aphase-difference detection signal, which is used in an autofocus (AF)operation using a phase-difference detection method (see, for example,Japanese Unexamined Patent Application Publication No. 2008-15476).

The image pickup apparatus having the above-described function displaysthe positions of the detected specific objects on the monitor and allowsa user to select one of the specific objects as a subject of distancemeasurement.

SUMMARY OF THE INVENTION

The phase-difference detection signal output from the AF module isgenerated on the basis of light from the object in predetermined areas(AF areas) set in an image capturing area. Therefore, if there is no AFarea at positions where the specific objects are detected, the distancemeasurement information regarding the specific objects is unobtainable.

Therefore, if there is no AF area at the position of the specific objectselected by the user, it is difficult to set the selected specificobject as a subject of distance measurement.

This problem occurs not only when the distance measurement informationis to be obtained but also when other image capturing informationregarding a desired specific object is to be obtained from apredetermined area set in the image capturing area.

Accordingly, it is desirable to provide an image pickup apparatuscapable of preventing a user from selecting a specific object for whichthe image capturing information is unobtainable in the process ofselecting a specific object for which the image capturing information isto be obtained.

An image pickup apparatus according to an embodiment of the presentinvention includes an image pickup device configured to capture an imageregarding an object image; object detecting means for detecting aspecific object in the captured image; image-capturing-informationobtaining means for obtaining image capturing information from apredetermined area set in an image capturing area; determining means fordetermining whether or not the image capturing information regarding thespecific object is obtainable from the predetermined area; and displaycontrol means for controlling a position display shown on a displayunit, the position display indicating a position of the specific object.The display control means changes a display mode of the position displayin accordance with the result of the determination performed by thedetermining means.

An image pickup apparatus according to another embodiment of the presentinvention includes an image pickup device configured to capture an imageregarding an object image; object detecting means for detecting aspecific object in the captured image; image-capturing-informationobtaining means for obtaining image capturing information from apredetermined area set in an image capturing area; and display controlmeans for controlling a position display shown on a display unit, theposition display indicating a position of the specific object. Thedisplay control means changes a display mode of the position display inaccordance with the positional relationship between an areacorresponding to the predetermined area and the specific object in thecaptured image.

According to the embodiments of the present invention, a specific objectfor which the image capturing information is unobtainable is preventedfrom being selected in the process of selecting a specific object forwhich the image capturing information is to be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating the external structure of an imagepickup apparatus according to a first embodiment of the presentinvention;

FIG. 2 is another diagram illustrating the external structure of theimage pickup apparatus according to the first embodiment of the presentinvention;

FIG. 3 is a vertical sectional view of the image pickup apparatusaccording to the first embodiment;

FIG. 4 is another vertical sectional view of the image pickup apparatusaccording to the first embodiment;

FIG. 5 is a block diagram illustrating the functional structure of theimage pickup apparatus according to the first embodiment;

FIG. 6 is a vertical sectional view of the image pickup apparatus in anEVF mode;

FIG. 7 is a diagram illustrating line images displayed in a finderwindow;

FIG. 8 is a diagram illustrating line images indicating AF areas;

FIG. 9 is a diagram illustrating an example of a display on a monitor inthe EVF mode;

FIG. 10 is a flowchart of a face-position display operation;

FIG. 11 is a diagram illustrating face frames indicating faces detectedby a face detection operation; and

FIG. 12 is a diagram illustrating another example of a display on amonitor of the image pickup apparatus in the EVF mode.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described below withreference to the accompanying drawings.

1. First Embodiment Structure

FIGS. 1 and 2 are diagrams illustrating the external view of an imagepickup apparatus 1A according to a first embodiment of the presentinvention. FIG. 1 is an external front view of the image pickupapparatus 1A. FIG. 2 is an external rear view of the image pickupapparatus 1A. The image pickup apparatus 1A is a single-lens reflexdigital camera having a replaceable lens.

As shown in FIG. 1, the image pickup apparatus 1A includes a camera mainbody (camera body) 2. A replaceable image-capturing lens unit(replaceable lens) 3 is detachably attached to the camera main body 2.

The image-capturing lens unit 3 basically includes a barrel 101, a lensgroup 37 (see FIG. 3) disposed in the barrel 101, and an aperture stop(not shown). The lens group 37 includes a focusing lens which movesalong an optical axis to change a focus position.

The camera main body 2 has an annular mount portion Mt to which theimage-capturing lens unit 3 is attached at a central position on thefront. A release button 89 for detaching the image-capturing lens unit 3is provided near the annular mount portion Mt.

The camera main body 2 has a mode-setting dial 82 at an upper leftposition on the front and a control-value-setting dial 86 at an upperright position on the front. The mode-setting dial 82 is operated to set(switch between) various modes (image-capturing modes including aportrait mode, a landscape mode, and a continuous image-capturing mode,a playback mode for playing back the captured images, a communicationmode for communicating data with external apparatuses, etc.). Thecontrol-value-setting dial 86 is operated to set control values used inthe respective image-capturing modes.

The camera main body 2 includes a grip portion 14 that can be gripped bya user at the left end on the front. A release button (shutter button)11 for issuing a command to start exposure is provided on a top surfaceof the grip portion 14. A battery-accommodating chamber and acard-accommodating chamber are provided in the grip portion 14. Thebattery-accommodating chamber accommodates, for example, four AAbatteries as a power source for the camera. The card-accommodatingchamber accommodates a recording medium (a memory card 90 (see FIG. 5)in this example) in a detachable manner. The memory card 90 stores dataof captured images.

The release button 11 is capable of detecting two states thereof: ahalf-pressed state (S1) and a fully pressed state (S2). When the releasebutton 11 is pressed halfway and the state S1 is detected, preparationoperations for capturing a still image of the object to be stored areperformed. For example, an AF control operation and an AE controloperation are performed as preparation operations. When the releasebutton 11 is further pressed and the state S2 is detected, animage-capturing operation for capturing the image to be stored isperformed. In the image-capturing operation, an exposure operation forthe object image is performed using an image pickup device (alsoreferred to as a “main image pickup device”) 5 (described below) and animage signal obtained by the exposure operation is subjected to imageprocessing.

Referring to FIG. 2, a monitor 12 is provided as a display unit at acentral position on the back of the camera main body 2. The monitor 12includes, for example, a color liquid crystal display (LCD). The monitor12 displays a menu screen used for setting image-capturing conditionsand the like. In addition, in the playback mode, the monitor 12 shows aplayback display of captured images stored in the memory card 90.

A finder window 10 is provided at an upper central position on the backof the camera main body 2. The object image obtained from theimage-capturing lens unit 3 is guided to the finder window 10. The usercan visually check an image that is equivalent to the object imagecaptured by the main image pickup device 5 by looking through the finderwindow 10. More specifically, the object image incident on animage-capturing optical system is reflected upward by a mirror mechanism6 (see FIG. 3) and is viewed by the user through an eyepiece 67. Thus,the user can determine the composition by looking through the finderwindow 10. When the state S2 of the release button 11 is detected andthe image-capturing operation for capturing the image to be stored isstarted, the mirror mechanism 6 is removed from an optical path of thelight which forms the object image. Accordingly, the light (light whichforms the object image) from the image-capturing lens unit 3 reaches themain image pickup device 5 and an image (image data) of the object canbe obtained.

A proximity sensor 13 is provided below the finder window 10. Theproximity sensor 13 detects the presence of a nearby object, and is usedto determine whether or not the finder is being used by the user.

A main switch 81 is provided at an upper left position of the monitor12. The main switch 81 is a two-position slide switch. The power of theimage pickup apparatus 1A is turned off when the main switch 81 is movedleft to an OFF position, and is turned on when the main switch 81 ismoved right to an ON position.

A direction selection key 84 and a display switch 9 are provided on theright of the monitor 12. The direction selection key 84 includes anannular operation button and is capable of individually detectingpressing operations of the operation button at four positions includingtop, bottom, left and right positions, and another four positionsincluding upper left, upper right, lower left, and lower rightpositions. In addition to the above-described pressing operations at theeight positions in total, the direction selection key 84 can also detecta pressing operation of a push button provided at the center.

The display switch 9 is a three-position slide switch. When the displayswitch 9 is at a position indicated as “OPTICAL” at the top, an opticalview finder (OVF) mode is selected and the object image is displayed inthe field of view of the optical finder. Accordingly, the user canperform the composition determination operation (also referred to as a“framing” operation) while visually checking the object image in thefield of view of the optical finder through the finder window 10.

When the display switch 9 is at a position indicated as “LIQUID CRYSTAL”at the bottom, an electronic view finder (EVF) mode is selected and alive view image of the object image is displayed on the monitor 12 as amoving image (live view display). Accordingly, the user can perform theflaming operation while visually checking the live view image displayedon the monitor 12.

In addition, when the display switch 9 is at a position indicated as“AUTO” in the middle, switching between the display in the field of viewof the optical finder (also referred to as “OVF view”) and the live viewis automatically performed depending on whether or not the user islooking through the finder window 10. Accordingly, the user can performthe flaming operation while visually checking the display in the fieldof view of the optical finder or the display of the live view inaccordance with the manner in which the image pickup apparatus 1A isused.

A setting button group 83 including a plurality of buttons for settingthe menu screen, deleting images, etc., is provided on the left of themonitor 12.

Next, the inner structure of the image pickup apparatus 1A will bedescribed. FIGS. 3 and 4 are vertical sectional views of the imagepickup apparatus 1A according to the first embodiment.

As shown in FIG. 3, the image pickup apparatus 1A includes a finder unit(also referred to as a “finder optical system”) 102, the mirrormechanism 6, a phase-difference AF module (hereinafter also referred tosimply as an AF module) 20, a shutter 4, the main image pickup device 5,and a sub image pickup device 7.

The main image pickup device (CCD sensor (also referred to simply asCCD) in this example) 5 is disposed on an optical axis L of a lens group37 included in the image-capturing lens unit 3, and is arranged along aplane perpendicular to the optical axis L. The main image pickup device5 receives an object image at an imaging surface thereof, and convertsthe received object image into an electric signal by photoelectricconversion. Thus, an image signal of the image to be stored isgenerated.

The shutter 4 is disposed immediately in front of the main image pickupdevice 5. The shutter 4 is a mechanical focal plane shutter whichincludes curtain members which move in the vertical direction, andperforms an operation of opening and closing an optical path of theobject light guided to the main image pickup device 5 along the opticalaxis L.

In addition, as shown in FIG. 3, the mirror mechanism 6 is provided onthe optical path (also referred to as an “image capturing optical path”)between the image-capturing lens unit 3 and the main image pickup device5.

The mirror mechanism 6 includes a main mirror 61 (main reflectivesurface) for reflecting light from the image-capturing optical systemupward. A portion or the entire body of the main mirror 61 is a halfmirror that allows a part of the light from the image-capturing opticalsystem to pass therethrough. The mirror mechanism 6 also includes a submirror 62 (sub reflective surface) for reflecting light that passesthrough the main mirror 61 downward.

The mirror mechanism 6 is formed as a so-called quick return mirror, andthe position of the mirror mechanism 6 can be changed between a positionin a mirror-down state and a position in a mirror-up state.

More specifically, in an image-capturing mode, the mirror mechanism 6 isset to the mirror-down state (see FIG. 3) until the state of the releasebutton 11 is changed to the fully pressed state S2, in other words,while the composition determination operation is being performed. In themirror-down state, the object light from the image-capturing lens unit 3is reflected upward by the main mirror 61 and is incident on the finderunit (also referred to as a “finder optical system”) 102 as observationlight. The detailed structure of the finder unit 102 will be describedin detail below.

A part of the object light passes through the main mirror 61, isreflected downward by the sub mirror 62, and is guided to the AF module20.

The AF module 20 includes a line sensor (focus detection sensors) or thelike which detects the focus information (also referred to as “distancemeasurement information”) of the object, and functions as an AF sensor.More specifically, the AF module 20 has a phase-difference detectionfunction of receiving the object light from distance measurement areas(also referred to as “focus areas” or “AF areas”) set in the imagecapturing area and generating a phase-difference detection signalcorresponding to the focus state of the object image. In other words, inthe mirror-down state set in the standby period, the AF module 20outputs the phase-difference detection signal on the basis of the objectlight guided to the AF module 20.

Thus, the AF module 20 functions as an image-capturing-informationobtaining unit for obtaining the distance measurement information fromthe AF areas, which are set at fixed positions in the image capturingarea, as image capturing information.

When the state of the release button 11 is changed to the fully pressedstate S2, the mirror mechanism 6 is set to the mirror-up state (see FIG.4) and the exposure operation is started.

More specifically, as shown in FIG. 4, the mirror mechanism 6 is liftedupward around a rotation axis 63 an is removed from the image capturingoptical path during the exposure operation. In more detail, the mainmirror 61 and the sub mirror 62 are moved upward so as not to block thelight from the image-capturing optical system. The light from theimage-capturing lens unit 3 reaches the main image pickup device 5 insynchronization with the time at which the shutter 4 is opened. The mainimage pickup device 5 generates an image signal of the object imagebased on the received light by photoelectric conversion. Thus, theobject image can be captured (image data can be obtained) by guiding thelight from the object to the main image pickup device 5 through theimage-capturing lens unit 3.

Functional Blocks

Functions of the image pickup apparatus 1A will now be described. FIG. 5is a block diagram illustrating the functional structure of the imagepickup apparatus 1A according to the first embodiment.

As shown in FIG. 5, the image pickup apparatus 1A includes thephase-difference AF module 20, an operating unit 80, an overallcontroller 100, the mirror mechanism 6, the shutter 4, the image pickupdevice 5, an A/D converter circuit 52, a digital signal processorcircuit 50, and an image memory 56.

The operating unit 80 includes various switches and buttons includingthe release button 11 (see FIG. 1). The overall controller 100 performsvarious operations in response to an input operation performed by theuser using the operating unit 80.

The main image pickup device 5 receives drive control signals (anaccumulation start signal and an accumulation stop signal) from a timingcontrol circuit (not shown), and performs an exposure operation (chargeaccumulation performed by causing photoelectric conversion) for anobject image formed on a light-receiving surface (imaging surface) inresponse to the received drive control signals. As a result, an imagesignal corresponding to the object image is obtained.

The image signal (analog signal) obtained by the main image pickupdevice 5 is converted into a digital signal by the A/D converter circuit52. The thus-obtained digital image signal is input to the digitalsignal processor circuit 50.

The digital signal processor circuit 50 subjects the image signal inputfrom the A/D converter circuit 52 to digital signal processes. Morespecifically, a black-level correction process, a white balance (WB)process, a γ correction process, etc., are performed. After the signalprocesses, the image signal (image data) is stored in the image memory56.

The image memory 56 is a high-speed-accessible image memory fortemporarily storing the generated image data and has a capacity largeenough to store data of a plurality of frames of images.

In the image-capturing operation for capturing an image to be stored,the image data that is temporarily stored in the image memory 56 issubjected to image processing (for example, compressing process) by theoverall controller 100 as necessary, and is then stored in the memorycard 90.

The sub image pickup device 7 basically has a function similar to thatof the main image pickup device 5, and serves as an image pickup device(auxiliary image pickup device) for capturing a live view image (forelectronic finder). More specifically, the sub image pickup device 7performs an exposure operation for an object image guided to the finderoptical system, and obtains an image signal regarding an image to bedisplayed as a live view image. It is not necessary that the sub imagepickup device 7 have a high resolution as long as an image signal fordisplaying the live view image can be generated. Therefore, the numberof pixels in the sub image pickup device 7 is generally smaller than thenumber of pixels in the main image pickup device 5.

The image data obtained by the sub image pickup device 7 is subjected topredetermined processes by the A/D converter circuit 52 and the digitalsignal processor circuit 50. Then, the thus-processed data istemporarily stored in the image memory 56 and is displayed on themonitor 12.

The overall controller 100 is formed of a microcomputer, and basicallyincludes a CPU, a RAM 120A, and a ROM 120B. The overall controller 100reads programs stored in the ROM 120B and causes the CPU to execute theprograms, thereby carrying out various functions.

The overall controller 100 executes the above-mentioned programs tocarry out the functions of a phase-difference AF controller 121, anobject detector 122, a drive controller 123, a determiner 124, a displaycontroller 125, and a mirror controller 126.

The phase-difference AF controller 121 performs an autofocus (AF)operation (also referred to as a “phase-difference AF operation”) by thephase-difference AF method. More specifically, the phase-difference AFcontroller 121 performs a lens-focus-position determination operationfor determining the position (lens focus position) of the image takinglens (to be more specific, the focusing lens) in a focused state on thebasis of the phase-difference detection signal output from the AF module20.

In addition, the phase-difference AF controller 121 operates inassociation with the drive controller 123 to perform a lens-drivingoperation for moving the image taking lens (focusing lens) to thedetermined lens focus position.

More specifically, the phase-difference AF controller 121 transmits acontrol signal to a lens controller 31 included in the image-capturinglens unit 3 via the drive controller 123. Accordingly, the lens driver38 is driven so as to move the focusing lens included in the lens group37 in the image-capturing lens unit 3 along an optical axis. Theposition of the focusing lens is detected by a lens position detector 39included in the image-capturing lens unit 3, and data representing theposition of the focusing lens is transmitted from the lens controller 31to the overall controller 100 in the camera main body 2.

The object detector 122 performs an object detection operation fordetecting a specific object in an image (auxiliary image) captured bythe sub image pickup device 7. In this example, a human face (alsoreferred to as a “face area”) is set as the specific object, and a facedetection operation for detecting a face area in the auxiliary image isperformed.

The face area may be detected by, for example, the following method.That is, first, a skin-colored area is extracted from the captured imageon the basis of the pixel value of each pixel. Then, if the area of theextracted skin-colored area is equal to or larger than a predeterminedthreshold, it is determined that the skin-colored area is a human face.Alternatively, a human face may also be detected by extracting specificparts, such as eyes and a mouth, of a human face from the captured imageby a common pattern recognition method. A face of an animal, such as acat and a dog, may also be set as a specific object.

Whether or not to execute the above-described face detection operationis determined on the basis of an operation (menu operation) performed bya user on a menu screen. More specifically, when a face detectionfunction (object detection function) is enabled (activated) by the menuoperation, the face detection operation is performed in the EVF mode. Ifthe face detection function is disabled (inactivated) by the menuoperation, the face detection operation is not performed.

Among the images successively captured by the sub image pickup device 7,the face detection operation is performed using every several frames ofimages (also referred to as “face detection images”). In other words,the face detection operation is performed once for several frames.

The determiner 124 determines whether or not the image capturinginformation can be obtained for the specific object detected by theobject detection operation. When, for example, distance measurementinformation regarding the specific object is to be obtained as the imagecapturing information, the determiner 124 determines whether or not theAF operation can be performed when the specific object is set as asubject of distance measurement.

The display controller 125 controls display contents shown on a displayunit including the monitor 12. For example, the display controller 125causes the monitor 12 to display continuous images on the basis of theimages that are continuously captured by the sub image pickup device 7.

The mirror controller 126 controls the operation of switching betweenthe state in which the mirror mechanism 6 is removed from the opticalpath (mirror-up state) and the state in which the mirror mechanism 6blocks the optical path (mirror-down state). The mirror controller 126switches between the mirror-up state and the mirror-down state bydriving a mirror switch motor (not shown).

Composition Determination Operation (Framing Operation)

The composition determination operation performed in the image pickupapparatus 1A will now be explained. As described above, in the imagepickup apparatus 1A, the user can slide the display switch 9 to selectwhether to perform the composition determination operation using theoptical finder in the OVF mode or to perform the compositiondetermination operation using the electronic finder in the EVF mode.FIG. 6 is a vertical sectional view of the image pickup apparatus 1A inthe EVF mode.

In the composition determination operation, the mirror mechanism 6 isset to the mirror-down state (see FIGS. 3 and 6). As described above, inthe mirror-down state, the object image from the image-capturing lensunit 3 is reflected upward by the main mirror 61 and is guided to thefinder unit 102 as observation light.

The finder unit 102 includes a penta-mirror 65, the eyepiece 67, aneyepiece shutter 68, the finder window 10, a beam splitter 70, the subimage pickup device 7, and a photometer 72.

The penta-mirror 65 includes a plurality of mirrors (reflectivesurfaces), and has a function of reflecting the object image such thatan erect image is obtained by vertically and horizontally reversing theobject image and a function of changing the optical path of the objectlight.

More specifically, the penta-mirror 65 includes two roof mirrors 65 aand 65 b arranged in the form of a delta roof, a surface 65 c fixed tothe roof mirrors (roof surfaces) 65 a and 65 b, and an optical-pathchanging mirror (reflective surface) 65 e.

The roof mirrors 65 a and 65 b are formed as an integral component 65 dby plastic molding and have a function of reflecting the object lighttwice so as to reverse the object image. The optical-path changingmirror 65 e has a function of changing the optical path of the objectlight depending on whether the composition determination operation isperformed using the optical finder or the electronic finder.

The eyepiece 67 has a function of guiding the erect object imageobtained by the penta-mirror 65 to the outside of the finder window 10.

The eyepiece shutter 68 is disposed between the eyepiece 67 and thefinder window 10. The eyepiece shutter 68 functions as a shutter capableof switching between a light blocking state in which the external lightis prevented from entering the image pickup apparatus 1A through thefinder window 10 and a non-blocking state in which the external lightthat enters through the finder window 10 is not blocked. For example,the eyepiece shutter 68 is set to the light blocking state in the EVFmode and is set to the non-blocking state in the OVF mode.

The beam splitter 70 has a function of dividing the optical path of theobject light incident on the beam splitter 70 into two optical paths.The sub image pickup device 7 is disposed on one of the two opticalpaths of the object light, and the photometer 72 is disposed on theother one of the two optical paths of the object light.

The photometer 72 receives the object light that passes through the beamsplitter 70 and an imaging lens 71, and performs a photometry process.More specifically, the photometer 72 receives the object light fromphotometry areas (also referred to as “AE areas”) set in the imagecapturing area and obtains photometry information (for example, objectbrightness information) regarding the amount of light of the objectimage. The photometry information obtained by the photometer 72 is used,for example, to set an exposure (AE) control value.

Thus, the photometer 72 functions as an image-capturing-informationobtaining unit for obtaining the photometry information from the AEareas, which are set at fixed positions in the image capturing area, asimage capturing information.

The flaming operation using the optical finder and the flaming operationusing the electronic finder will now be described in detail. FIG. 7 is adiagram illustrating line images Gv shown in the finder window 10. FIG.8 is a diagram illustrating line images Gvf indicating the AF areas.

First, the flaming operation using the optical finder will be described.

As shown in FIG. 3, in the OVF mode, the mirror mechanism 6 is disposedon the optical path of the object image from the image-capturing lensunit 3, and the object image is guided to the finder window 10 throughthe main mirror 61, the penta-mirror 65, and the eyepiece 67. Thus, themain mirror 61 and the finder optical system 102 including thepenta-mirror 65 and the eyepiece 67 are capable of guiding the objectimage obtained by the image-capturing optical system to the finderwindow 10.

More specifically, the object light that passes through theimage-capturing lens unit 3 is reflected upward by the main mirror 61and is focused on a focusing glass 64. The object light focused on thefocusing glass 64 passes through the focusing glass 64 and is incidenton the penta-mirror 65, which changes the optical path of the objectlight. Then, the object light passes through the eyepiece 67 and travelstoward the finder window 10 (see an optical path PA in FIG. 3). Thus,the object image is guided to the finder window 10 along the opticalpath PA and reaches an eye of the user (observer), so that the user canvisually check the object image.

Thus, in the OVF mode, the user can determine the composition whilevisually checking the object image by looking through the finder window10.

As shown in, for example, FIG. 7, in the optical finder, the line images(also referred to as “line drawings” or “target marks”) Gv, whichindicate focusing positions and/or photometry positions with respect tothe object, are superimposed on the object image in the finder window10. The line images Gv include a plurality of line images correspondingto image capturing conditions regarding the focusing operation and/orthe exposure operation.

In the image pickup apparatus 1A, the focus detection sensors includedin the AF module 20 are disposed at positions corresponding to nine lineimages Gvf (see FIG. 8) in the line images Gv shown in FIG. 7. The nineline images Gvf indicate the AF areas in the image capturing area atwhich the focus information can be obtained. In the image pickupapparatus 1A, the object can be brought into focus by using the focusdetection sensors provided at the nine AF areas.

The line images Gv are drawn by scratching the top surface of thefocusing glass 64, which is formed as a transparent component. Thus, theline images Gv, which are superimposed on the object image and guided tothe finder window 10, are drawn on the focusing glass 64 disposed on theoptical path PA which guides the object light from the image taking lensto the finder window 10.

Next, the flaming operation using the electronic finder will bedescribed.

As shown in FIG. 6, also in the EVF mode, the mirror mechanism 6 isdisposed on the optical path of the object image from theimage-capturing lens unit 3. The object light that passes through theimage-capturing lens unit 3 is reflected upward by the main mirror 61and is focused on the focusing glass 64. The object light focused on thefocusing glass 64 passes through the focusing glass 64 and is incidenton the penta-mirror 65, which changes the optical path of the objectlight. The optical path is further changed by the beam splitter 70 sothat the object light passes through an imaging lens 69 (imaging opticalsystem) and is re-focused on the imaging surface of the sub image pickupdevice 7 (see the light path PB in FIG. 6).

Thus, in the EVF mode, the object image is guided to the sub imagepickup device 7 along an optical path PB, which is different from theoptical path PA used in the OVF mode.

In the finder unit 102, the optical path is changed by changing theangle (installation angle relative to the camera main body 2) of theoptical-path changing mirror 65 e in accordance with the finder mode.

More specifically, the optical-path changing mirror 65 e is rotatablearound an axis AX1 in response to a sliding movement of the displayswitch 9. In the EVF mode (see FIG. 6), the optical-path changing mirror65 e is rotated from the position thereof in the OVF mode (see FIG. 3)by a predetermined angle AN around the axis AX1 in the direction shownby arrow AR1.

The overall controller 100 determines whether to perform the compositiondetermination operation using the optical finder or to perform thecomposition determination operation using the electronic finder on thebasis of the result of detection obtained by an angle detector (notshown) which detects the angle of the optical-path changing mirror 65 earound the axis AX1.

In the state shown in FIG. 3, it is determined from the angle of theoptical-path changing mirror 65 e that the composition determinationoperation is to be performed using the optical finder. Accordingly,processes of stopping the supply of electricity to the sub image pickupdevice 7 and turning off the monitor 12 are performed. In the stateshown in FIG. 6, it is determined from the angle of the optical-pathchanging mirror 65 e that the composition determination operation is tobe performed using the electronic finder. Accordingly, processescorresponding to the EVF mode, that is, processes of supplyingelectricity to the sub image pickup device 7 and displaying a live viewimage on the monitor 12 are performed.

Thus, in the EVF mode, the position of the optical-path changing mirror65 e is changed so as to change the optical path of the object light inthe finder unit 102. As a result, the object light passes through thebeam splitter 70 and the imaging lens 69 and reaches the sub imagepickup device 7.

As described above, the sub image pickup device 7 receives the objectlight which travels along the optical path PB and reaches the sub imagepickup device 7, and periodically captures an image regarding the objectimage at a small time interval (for example, 1/60 seconds). The imagescaptured in time series are successively displayed on the monitor 12 asa moving image (live view display).

Accordingly, the user can determine the composition while visuallychecking the moving image (live view image) displayed on the monitor 12.

The imaging lens 69, the beam splitter 70, and the sub image pickupdevice 7 are disposed at positions where they do not block the lightwhich travels from the optical-path changing mirror 65 e to the eyepiece67 in the OVF mode (at positions above the eyepiece 67 in thisembodiment).

Thus, in the image pickup apparatus 1A, switching between the OVF modeand the EVF mode is performed by changing the optical path of the objectimage by changing the position of the optical-path changing mirror 65 ein the finder unit 102.

Monitor Display in EVF Mode

The monitor display in the EVF mode will now be explained. FIG. 9 is adiagram illustrating an example of a display on the monitor 12 in theEVF mode. In FIG. 9, the object is not shown for simplicity.

As described above, in the EVF mode, the object is displayed on themonitor 12 as a moving image. In addition, as shown in FIG. 9, the lineimages Gv are also displayed on the monitor 12 together with the object(not shown in FIG. 9) in the EVF mode.

In addition, if the face detection function is enabled in the EVF modeand a face area is detected, a display (also referred to as a “faceposition display”) indicating the position of the detected face area isalso shown on the monitor 12. More specifically, in the case where theface detection function is enabled, if a person is included in theobject image, the face of the person is detected and the position of theface is displayed on the monitor 12.

The position of the detected face is shown by a frame (hereinafter alsoreferred to as a “face frame” or a “face display frame”) which surroundsthe detected face area. In FIG. 9, two face frames WK1 and WK2 aredisplayed. A display mode of the face frame WK on the monitor 12 differsdepending on the positional relationship between the detected face areaand the AF areas.

The face position display operation performed in the EVF mode will nowbe described with reference to the flowchart of the face positiondisplay operation shown in FIG. 10. FIG. 11 is a diagram illustratingface frames WK indicating faces detected by the face detectionoperation.

In the image pickup apparatus 1A, the face position display operationshown in FIG. 10 is performed when the EVF mode is set.

More specifically, first, it is determined whether or not the objectdetection function (face detection function in this example) is enabledin step SP11. If it is determined that the object detection function isenabled, the process proceeds to step SP12. If it is determined that theobject detection function is not enabled (disabled), the process waitsuntil the object detection function is enabled.

In step SP12, it is determined whether or not a specific object isdetected in the object detection operation. If a specific object isdetected, the process proceeds to step SP13. If no specific object isdetected, the process proceeds to step SP16.

In step SP13, information regarding the position of the specific objectin the auxiliary image is obtained. More specifically, the coordinatesof each pixel in the area of the specific object (also referred to as a“detected object area”) in the auxiliary image are obtained.

Then, in step SP14, the determiner 124 determines whether or not theimage capturing information regarding the specific object is obtainable.

When, for example, the distance measurement information regarding thespecific object is to be obtained as the image capturing information, itis determined whether or not the specific object can be selected as thesubject of distance measurement. More specifically, it is determinedwhether or not the detected object area overlaps any one of AF areas onthe auxiliary image (also referred to as “corresponding AF areas” or“equivalent AF areas”), which correspond to the AF areas set in theimage capturing area.

Whether or not the detected object area overlaps any one of thecorresponding AF areas on the auxiliary image can be determined by, forexample, the following method. That is, the coordinates of each pixel inthe corresponding AF areas are compared with the coordinates of eachpixel in the detected object area. Thus, it is determined whether or notat least some of the pixels in the corresponding AF areas are includedin the detected object area.

The coordinates of each pixel in the corresponding AF areas on theauxiliary image are obtained at the time when the image pickup apparatus1A is manufactured, and are stored in the ROM 120B of the image pickupapparatus 1A in advance.

Thus, in step SP14, it is determined that the detected object areaoverlaps one or more of the corresponding AF areas on the auxiliaryimage if it is determined that at least some of the pixels in thecorresponding AF areas are included in the detected object area. In sucha case, it is determined that the image capturing information regardingthe specific object can be obtained.

Referring to FIG. 10, in step SP15, the display controller 125 causesthe monitor 12 to display the position of the detected specific object.

The display mode of the position on the monitor 12 differs depending onthe result of the above-described determination of whether or not thedetected object area is in the overlapping state.

For example, referring to FIG. 11, a case is considered in which fourface areas are detected in the object detection operation (facedetection operation). In FIG. 11, four face frames WK1 to WK4 aredisplayed. In this case, it is determined whether or not each of thefour face areas overlaps the corresponding AF areas in step SP14.

As a result of the determination, the face areas (face frames WK3 andWK4 in FIG. 11) which do not overlap the corresponding AF areas and theface areas (face frames WK1 and WK2 in FIG. 11) which overlap thecorresponding AF areas are determined.

Then, in step SP15, the face frames WK1 and WK2 indicating the faceareas which overlap the corresponding AF areas are displayed on themonitor 12 while the face frames WK3 and WK4 indicating the face areaswhich do not overlap the corresponding AF areas are set to a non-displaymode (see FIG. 9).

Thus, in the image pickup apparatus 1A, the positions of the face areaswhich overlap the corresponding AF areas are displayed but the positionsof the face areas which do not overlap the corresponding AF areas arenot displayed (are set to a non-display mode).

As described above, in the image pickup apparatus 1A, it is determinedwhether or not the image capturing information regarding the specificobject can be obtained from a predetermined area set in the imagecapturing area. Then, the display mode of the position of the specificobject is changed in accordance with the result of the determination.Accordingly, the user can determine whether or not the image capturinginformation regarding the specific object can be obtained from thepredetermined area on the basis of the display mode of the position ofthe specific object. As a result, when a specific object for which theimage capturing information is to be obtained is selected by the user,the user is prevented from selecting a specific object for which theimage capturing information is unobtainable.

2. Second Embodiment

Next, a second embodiment of the present invention will be described.

In the image pickup apparatus 1A according to the first embodiment, thedistance measurement information regarding the specific object isobtained as the image capturing information. However, in an image pickupapparatus 1B according to the second embodiment, photometry informationregarding the specific object is obtained as the image capturinginformation. FIG. 12 is a diagram illustrating an example of a displayon the monitor 12 in the image pickup apparatus 1B in the EVF mode.

The structure and functions of the image pickup apparatus 1B accordingto the second embodiment are similar to those of the image pickupapparatus 1A according to the first embodiment (see FIGS. 1 to 6) exceptthe photometry information regarding the specific object is obtained asthe image capturing information. In the second embodiment, componentssimilar to those of the first embodiment are denoted by the samereference numerals, and explanations thereof are thus omitted.

The determiner 124 in the image pickup apparatus 1B determines whetheror not a photometry process can be performed when the specific objectdetected in the object detection operation is a photometry subject, inother words, whether or not the specific object can be selected as thephotometry subject.

The display mode of the face frame WK on the monitor 12 differsdepending on the result of the determination performed by the determiner124.

For example, referring to FIG. 11, a case is considered in which fourface areas are detected in the object detection operation. In such acase, it is determined whether or not each of the four face areasoverlaps photometry areas on the auxiliary image (also referred to as“corresponding photometry areas” or “equivalent photometry areas”),which correspond to photometry areas set in the image capturing area.

As a result of the determination, the face areas which do not overlapthe corresponding photometry areas (face frames WK2, WK3, and WK4 whichdo not overlap line images Gvs indicating the photometry areas in FIG.11) and the face area which overlaps the corresponding photometry areas(face frame WK1 in FIG. 11) are determined.

Then, the display controller 125 causes the monitor 12 to display theface frame WK1 indicating the face area which overlaps the correspondingphotometry areas, and the face frames WK2, WK3, and WK4 indicating theface areas which do not overlap the corresponding photometry areas areset to a non-display mode (see FIG. 12).

Thus, in the image pickup apparatus 1B, the positions of the face areaswhich overlap the corresponding photometry areas are displayed but thepositions of the face areas which do not overlap the correspondingphotometry areas are not displayed (are set to a non-display mode).Accordingly, the positions of the face areas which can be selected asthe photometry subject are shown in the monitor 12, while the positionsof the face areas which are not selectable as the photometry subject arenot displayed. As a result, the user is prevented from selecting a facearea which is not selectable as the photometry subject.

3. Modifications

Although the embodiments of the present invention have been described,the present invention is not limited to the above-described embodiments.

For example, in each of the above-described embodiments, the position ofeach face area is indicated by the frame WK which surrounds the detectedface area. However, the present invention is not limited to this.

For example, the position of the detected face area may also beindicated by an icon.

In addition, in each of the above-described embodiments, whether or notto display the position of the face area is determined in accordancewith the result of the determination of whether or not the face area isin the overlapping state. However, the present invention is not limitedto this.

For example, the face frame WK can be displayed in different colors,shapes, etc., in accordance with the result of the determination ofwhether or not the face area is in the overlapping state. Morespecifically, as a modification of the first embodiment, the positionsof the face areas which overlap the corresponding AF areas may beindicated by face frames WK drawn by solid lines, and the positions ofthe face areas which do not overlap the corresponding AF areas may beindicated by face frames WK drawn by dashed lines. Alternatively, thedisplay of the positions of the face areas which do not overlap thecorresponding AF areas and the display of the positions of the faceareas which overlap the corresponding AF areas can be distinguished fromeach other by causing the face frames WK indicating the face areas whichdo not overlap the corresponding AF areas to flash.

In addition, in the first embodiment, whether or not each specificobject detected in the object detection operation can be selected as thesubject of distance measurement is determined on the basis of whether ornot the detected object area overlaps any one of the corresponding AFareas. However, the present invention is not limited to this.

For example, the eyes of the specific object may be detected in theobject detection operation, and whether or not the specific object canbe selected as the subject of distance measurement may be determined onthe basis of whether or not there is a corresponding AF area within acertain distance from the eyes. In this case, it is determined that thespecific object can be selected as the subject of distance measurementwhen there is an AF area within the certain distance from the eyes ofthe specific object.

In addition, there is a high possibility that a specific part (body inthis example) is positioned below the face of a person. Therefore, itmay also be determined that the specific object can be selected as thesubject of distance measurement when an AF area is positioned below theface area detected as the specific object.

In addition, in the first embodiment, the focus information is obtainedby the focus detection sensors included in the AF module 20. However,the present invention is not limited to this.

More specifically, pixels for phase difference detection (also referredto as “AF pixels”) which are capable of obtaining the focus informationmay be provided on the light receiving surface of the main image pickupdevice 5 (or the sub image pickup device 7). In such a case, anautomatic focusing operation by the phase-difference detection method(also referred to as a “phase-difference AF operation using an imagepickup device”) can be performed using output signals from the AFpixels.

In this case, the determiner 124 determines whether or not the detectedobject area overlaps the corresponding AF areas on the auxiliary imagewhich correspond to the AF areas defined by the positions of the AFpixels, and the display mode of the position of the specific object isdetermined on the basis of the result of the determination.

The present application contains subject matter related to thatdisclosed in Japanese Priority Patent Application JP 2008-112232 filedin the Japan Patent Office on Apr. 23, 2008, the entire content of whichis hereby incorporated by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. An image pickup apparatus, comprising: an image pickup deviceconfigured to capture an image regarding an object image; objectdetecting means for detecting a specific object in the captured image;image-capturing-information obtaining means for obtaining imagecapturing information from a predetermined area set in an imagecapturing area; determining means for determining whether or not theimage capturing information regarding the specific object is obtainablefrom the predetermined area; and display control means for controlling aposition display shown on a display unit, the position displayindicating a position of the specific object, wherein the displaycontrol means changes a display mode of the position display inaccordance with the result of the determination performed by thedetermining means.
 2. The image pickup apparatus according to claim 1,wherein the display control means sets the position display to anon-display mode if the determining means determines that the imagecapturing information regarding the specific object is unobtainable fromthe predetermined area.
 3. The image pickup apparatus according to claim2, wherein the determining means determines that the image capturinginformation regarding the specific object is obtainable when an areacorresponding to the predetermined area and an area of the specificobject overlap each other in the captured image.
 4. The image pickupapparatus according to claim 3, wherein the predetermined area includesan AF area, and wherein the image-capturing-information obtaining meansobtains distance measurement information from the AF area.
 5. The imagepickup apparatus according to claim 3, wherein the predetermined areaincludes an AE area, and wherein the image-capturing-informationobtaining means obtains photometry information from the AE area.
 6. Theimage pickup apparatus according to claim 1, wherein the display controlmeans changes the display mode of the position display between a case inwhich the determining means determines that the image capturinginformation regarding the specific object is unobtainable and a case inwhich the determining means determines that the image capturinginformation regarding the specific object is obtainable.
 7. An imagepickup apparatus, comprising: an image pickup device configured tocapture an image regarding an object image; object detecting means fordetecting a specific object in the captured image;image-capturing-information obtaining means for obtaining imagecapturing information from a predetermined area set in an imagecapturing area; and display control means for controlling a positiondisplay shown on a display unit, the position display indicating aposition of the specific object, wherein the display control meanschanges a display mode of the position display in accordance with thepositional relationship between an area corresponding to thepredetermined area and the specific object in the captured image.
 8. Animage pickup apparatus, comprising: an image pickup device configured tocapture an image regarding an object image; an object detector detectinga specific object in the captured image; an image-capturing-informationobtaining unit obtaining image capturing information from apredetermined area set in an image capturing area; a determinerdetermining whether or not the image capturing information regarding thespecific object is obtainable from the predetermined area; and a displaycontroller controlling a position display shown on a display unit, theposition display indicating a position of the specific object, whereinthe display controller changes a display mode of the position display inaccordance with the result of the determination performed by thedeterminer.
 9. An image pickup apparatus, comprising: an image pickupdevice configured to capture an image regarding an object image; anobject detector detecting a specific object in the captured image; animage-capturing-information obtaining unit obtaining image capturinginformation from a predetermined area set in an image capturing area;and a display controller controlling a position display shown on adisplay unit, the position display indicating a position of the specificobject, wherein the display controller changes a display mode of theposition display in accordance with the positional relationship betweenan area corresponding to the predetermined area and the specific objectin the captured image.